What is a namespace ... really?

James Tauber jtauber at jtauber.com
Sun Jan 17 04:25:22 GMT 1999

>>Me, myself, I think this is a bogus use of URIs.  What you are
>>really using is DNS, and you don't need to use fake URIs to do so;
>>cf. the IOTP spec.
>That's a good point - clearly the DNS is a key part of this.  But
>you might want more than one namespace per domain, so what we need
>is a DNS address plus some more identifying stuff; a bill that the
>URI seems to fill, so why re-invent it.

IMHO, the key is a hierarchical naming scheme. DNS provides the first few
levels of the hierarchy; the path provides the remaining levels.

It's worth noting that only the globally unique naming aspect of DNS is
utilised - not the resolution mechanism. This is what seems to confuse
people. They think that the resource at the other end of the URI is what
determines the namespace. It's not the resource that determines the
namespace (the resource might not even exist), it is just the URI, or
perhaps even more precisely: the string of characters that is the URI.

Maybe this *is* a bogus use of URIs. Other alternatives include:

    * domain name + some string      eg ("w3.org","XSL FO")
    * ISO 9070 public identifiers

Note that because these things never get resolved, it does not matter that
there isn't a resolution mechanism for the first one or that there is no
widespead use of delegating catalogs for the latter. All that matters is a
recognised hierarchical naming scheme with a root authority.

James Tauber / jtauber at jtauber.com / www.jtauber.com
Associate Researcher, Electronic Commerce Network
Curtin University of Technology, Perth, Western Australia

Maintainer of : www.xmlinfo.com,  www.xmlsoftware.com and www.schema.net

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